<?php
class SchlauIoProxy {
    private $apiUrl;
    private $salt;
    public function __construct($apiUrl, $salt) {
        $this->apiUrl = $apiUrl;
        $this->salt = $salt;
    }
    public function main() {
        header('Access-Control-Allow-Origin: *');
        header('Access-Control-Allow-Methods: POST');
        $json = file_get_contents('php://input');
        $postObj = json_decode($json);
        if(isset($postObj->event)){
            if($postObj->actor == 'not set') {
                $postObj->actor = $this->generateActorIdentifier($postObj->projectId);
            }
            $json = json_encode($postObj);
            echo $this->postJsonViaCurl($json);
        }
        elseif(isset($postObj->projectId)) {
            echo json_encode($this->generateActorIdentifier($postObj->projectId));
        }
    }
    private function generateActorIdentifier($projectId) {
        $salt = hash("sha512", $projectId . $this->salt);
        $userAgent = $_SERVER['HTTP_USER_AGENT'];
        $acceptLanguage = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? $_SERVER['HTTP_ACCEPT_LANGUAGE'] : '';
        $remoteAddress = $_SERVER['REMOTE_ADDR'];
        return hash("sha512"  ,$salt . $userAgent . $acceptLanguage . $remoteAddress);
    }
    private function postJsonViaCurl($json) {
        $curl = curl_init($this->apiUrl);
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
        curl_setopt($curl, CURLOPT_POST, true);
        curl_setopt($curl, CURLOPT_POSTFIELDS, $json);
        $response = curl_exec($curl);
        curl_close($curl);
        return $response;
    }
}
$schlauIoProxy = new SchlauIoProxy('https://app.schlau.io/api/in', 'rRLnuBp*-W30');
$schlauIoProxy->main();